Tuesday, 30 September 2014

Triassic Sandstone & Mudstone

A general view of Cedar Road Quarry in 1997

The first time that I saw this site, way back in 1997, a very brief survey clearly demonstrated that the extensive and easily accessible rock outcrops makes this an ideal site for educational purposes, at all levels. At the time of my visit, a vehicle and a couple of workmen were being gainfully employed in cutting grass, pruning a variety of shrubs and other invasive vegetation - and taking away the large amount of rubbish that inevitably accumulates in very many forgotten geological sites like this.

Sandstone and Mudstone - 2007
On my next visit, 10 years later, whilst producing the Doncaster Geodiversity Assessment, it seemed obvious to me that this former Adventure Playground was no longer actively managed by the local authority - with beer cans and medical syringes just being a few pieces of social debris that could be found there. 

Apart from a few brambles, which stopped me from getting as close enough to a rock outcrop as I would have liked to have done, my former observations concerning the educational value still held true - as there was plenty of rock to be seen.

At this moment - during winter - I had both the time and the technological benefit of using a Global Positioning Device to pinpoint the various places of geological interest that I had seen before, and could still easily see. I also discovered a few Quaternary rocks that I hadn't noticed before.

Glacial Till and Glaciofluvial Deposits

Although the Sherwood Sandstone Group, of Triassic age, forms the bedrock beneath 70% of the borough of Doncaster and it does form gentle escarpments and other topographical features in places, most of it is buried by unconsolidated Quaternary sediments. In the remote eastern part of the borough, this very friable sandstone has been exploited, along with the overlying sand and gravel, for aggregates and it is well exposed in several active and redundant quarries. However, except where seen in railway cuttings, exposures of rock in the public domain are extremely rare.  

A general view of Cedar Road Quarry in 2007

When returning again, this month, with students from XP School, I could hardly believe my eyes. Taking into account a very warm, wet year that has disrupted so many of the annual cycles of plants and birds, amongst other things, I just couldn't see a single place where they could readily undertake any of their allotted tasks - without cutting through the overgrowth.

Sunday, 28 September 2014

Conservation Meets Education

An old fashioned measuring tool

Out of the blue, I was recently contacted by XP School in Doncaster, to ask if I would be prepared to act as a “geology expert” and accompany a group of first year students on a field trip to investigate the geology around the Don Gorge.

Martin Said, a teacher at the school, was impressed by the Doncaster Geodiversity Assessment that I co-produced for Doncaster MBC in 2007, whilst working for the British Geological Survey. Having previously undertaken a survey of the 26 geological sites that formed the basis of this report back in 1997, with the South Yorkshire RIGS (Regionally Important Geological Sites) Group, I was considered to be the ideal person to undertake this job.

A 20x magnification hand lens
Although a great effort was made by the South Yorkshire RIGS Group to highlight the very best sites in the county for their educational value, none of the sites identified in South Yorkshire had been used by any school for their field trips - to the best of my knowledge - and so I was very pleased to help.

25 students, split into two groups, were taken to 3 sites that were considered to provide the best introduction to the geology of Doncaster.

With each group travelling in an opposite direction, and meeting up for lunch in the middle, a total of 6 hours was spent out in the field to undertake the following tasks:

1)   Measure and draw the rock outcrop.
2)   Annotate the drawings.
3)  Closely investigate the rock outcrop and analyse the lithologies seen.

Grain Size and Roundness Charts